Question

I’m using Spring rest with below code base:

When I invoke /info by passing string value in request body, I’m expecting the below response if this value is not present in my backend database.

{"output":-10} 

but instead it returns me below response:

{"id": 0, "output":-10} 

Can any one tell me how to get rid of this id default value? If there is a boolean variable in JSON mapper, then that would also get returned as

{"id": 0, "booleanVar": false, "output":-10} 

Can any one tell me how to get rid of this default value?

Controller.java

@RequestMapping(value = "heartbeat", method = RequestMethod.GET, consumes="application/json")
public ResponseEntity<String> getHeartBeat() throws Exception {
    String curr_time = myService.getCurrentTime();      
    return MyServiceUtil.getResponse(curr_time, HttpStatus.OK);
}

@RequestMapping(value = "info", method = RequestMethod.POST, consumes="application/json")
public ResponseEntity<String> getData(@RequestBody String body) throws Exception {
    ....
    myInfo = myService.getMyInfo(myServiceJson);
    return MyServiceUtil.getResponse(myInfo, responseHeader, HttpStatus.OK);
}

MyService.java

@Override
public String getCurrentTime() throws Exception {
    String currentDateTime = null;
    MyServiceJson json = new MyServiceJson();
    ObjectMapper mapper = new ObjectMapper().configure(SerializationConfig.Feature.DEFAULT_VIEW_INCLUSION, false);

    try {           
        Date currDate = new Date(System.currentTimeMillis());
        currentDateTime = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss").format(currDate);           
        json.setCurrentDateTime(currentDateTime);

        ObjectWriter writer = mapper.writerWithView(Views.HeartBeatAPI.class);
        return writer.writeValueAsString(json);

    } catch (Exception e) {
        throw new Exception("Excpetion in getCurrentTime: ", HttpStatus.BAD_REQUEST);           
    }
}

@Override
public String getMyInfo(MyServiceJson myServiceJson) throws Exception {             
    MyServiceJson json = new MyServiceJson();
    json.setFirstName("hhh");
    json.setLastName("abc");

    ObjectMapper mapper = new ObjectMapper();
    return mapper.writeValueAsString(json);
}

Views.java

public class Views {
    public static class HeartBeatAPI {  }
}

MyServiceJson.java

@JsonSerialize(include = Inclusion.NON_NULL)
public class MyServiceJson {
    private int id;
    private String firstName;   
    private String lastName;

    @JsonView(Views.HeartBeatAPI.class) 
    private String currentDateTime;

    // Getter/Setter for the above variables here
    .....

}

Answer 1

Use Integer class instead of int primitive type. Primitive types always hold default values, where class type defaults to null.